[HIGH] CVE-2020-15094: Prevent RCE when calling untrusted remote with CachingHttpClient

PKSA-6pwr-137g-8814 CVE-2020-15094 GHSA-754h-5r27-7x3r

Affected package: symfony/symfony

Affected version: >=4.3.0,<4.4.0|>=4.4.0,<4.4.13|>=5.0.0,<5.1.0|>=5.1.0,<5.1.5

Reported by:
GitHub, FriendsOfPHP/security-advisories